Electric Park Brake Actuators: Notes

The EPB actuators are electro mechanical positioning units attached to the calipers of the rear brakes. Each actuator incorporates a reversible electric motor driving an output shaft via a drive belt and planetary gear cluster.

The output shaft of the EPB actuator is engaged in the splined end of a spindle, which is inside the caliper piston and screwed into a thrust nut. Operation of the electric motor turns the spindle and produces linear movement of the thrust nut, to apply a target clamp load to the brake pads.